Systems and methods for receiver beaconing in wireless power systems

ABSTRACT

A wireless power transmission system includes a transmitter antenna, a sensor, a demodulation circuit, and a transmitter controller. The sensor is configured to detect electrical information indicative of data signals encoded in the transmission by a receiver. The demodulation circuit is configured to apply automatic bias control and gain control to the electrical information to generate a modified electrical information signal, detect a change in the modified electrical information signal, and generate alerts based on said change, indicative of the data signals. The transmitter controller is configured to perform a beaconing sequence to determine a coupling between the transmitter antenna and the at least one other antenna, determine the automatic bias control and the automatic gain control, for the demodulation circuit based on the beaconing sequence, receive the plurality of data alerts from the demodulation circuit, and decode the plurality of data alerts into the wireless data signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to, U.S. non-provisional application Ser. No. 17/164,535, filed on Feb. 1, 2021, and entitled “SYSTEMS AND METHODS FOR RECEIVER BEACONING IN WIRELESS POWER SYSTEMS,” which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to systems and methods for wireless transfer of electrical power and/or electrical data signals, and, more particularly, to beaconing systems for dynamically configuring demodulation circuits for wireless power transfer systems.

BACKGROUND

Wireless connection systems are used in a variety of applications for the wireless transfer of electrical energy, electrical power, electromagnetic energy, electrical data signals, among other known wirelessly transmittable signals. Such systems often use inductive and/or resonant inductive wireless power transfer, which occurs when magnetic fields created by a transmitting element induce an electric field and, hence, an electric current, in a receiving element. These transmitting and receiving elements will often take the form of coiled wires and/or antennas.

Transmission of one or more of electrical energy, electrical power, electromagnetic energy and/or electronic data signals from one of such coiled antennas to another, generally, operates at an operating frequency and/or an operating frequency range. The operating frequency may be selected for a variety of reasons, such as, but not limited to, power transfer characteristics, power level characteristics, self-resonant frequency restraints, design requirements, adherence to standards bodies' required characteristics (e.g. electromagnetic interference (EMI) requirements, specific absorption rate (SAR) requirements, among other things), bill of materials (BOM), and/or form factor constraints, among other things. It is to be noted that, “self-resonating frequency,” as known to those having skill in the art, generally refers to the resonant frequency of a passive component (e.g., an inductor) due to the parasitic characteristics of the component.

When such systems operate to wirelessly transfer power from a transmission system to a receiver system via coils and/or antennas, it is often desired to simultaneously or intermittently communicate electronic data from one system to the other. To that end, a variety of communications systems, methods, and/or apparatus have been utilized for combined wireless power and wireless data transfer. In some example systems, wireless power transfer related communications (e.g., validation procedures, electronic characteristics data communications, voltage data, current data, device type data, among other contemplated data communications) are performed using other circuitry, such as optional Bluetooth chipsets and/or antennas for data communications, among other known communications circuits and/or antennas.

SUMMARY

However, using additional antennas and/or circuitry can give rise to numerous disadvantages, and as such, in-band data transfer may be desired. Nonetheless, such in-band transfer of data may itself become ineffective or inefficient when the relative positions of the data sender and data receiver vary too greatly.

Sensitive demodulation circuits that allow for fast and accurate in-band communications, regardless of the relative positions of the sender and receiver within the power transfer range, are desired. The demodulation circuit of the wireless power transmitters disclosed herein is a circuit that is utilized to, at least in part, decode or demodulate ASK (amplitude shift keying) signals down to alerts for rising and falling edges of a data signal. So long as the controller is programmed to properly process the coding schema of the ASK modulation, the transmission controller will expend less computational resources than it would if it were required to decode the leading and falling edges directly from an input current or voltage sense signal from the sensing system. To that end, the computational resources required by the transmission controller to decode the wireless data signals are significantly decreased due to the inclusion of the demodulation circuit.

This may in turn significantly reduce the BOM for the demodulation circuit, and the wireless transmission system as a whole, by allowing usage of cheaper, less computationally capable processor(s) for or with the transmission controller.

However, the throughput and accuracy of an edge-detection coding scheme depends in large part upon the system's ability to quickly and accurately detect signal slope changes. Moreover, in environments wherein the distance between, and orientations of, the sender and receiver may change dynamically, the magnitude of the received power signal and embedded data signal may also change dynamically. This circumstance may cause a previously readable signal to become too faint to discern, or may cause a previously readable signal to become saturated.

In accordance with one aspect of the disclosure, a wireless power transmission system is disclosed. The wireless power transmission system includes a transmitter antenna, at least one sensor, a demodulation circuit, and a transmitter controller. The transmitter antenna is configured to couple with at least one other antenna of at least one other system and transmit alternating current (AC) wireless signals to the at least one other antenna, the AC wireless signals including wireless power signals and wireless data signals, the wireless data signals generated by altering electrical characteristics of the AC wireless signals at the at least one other system. The at least one sensor is configured to detect electrical information associated with the electrical characteristics of the AC wireless signals, the electrical information including one or more of a current of the AC wireless signals, a voltage of the AC wireless signals and a power level of the AC wireless signals. The demodulation circuit is configured to (i) receive the electrical information from the at least one sensor, (ii) apply automatic bias control and gain control to the electrical information to generate a modified electrical information signal (iii) detect a change in the modified electrical information signal, (iv) determine if the change in the modified electrical information signal meets or exceeds one of a rise threshold or a fall threshold, (v) if the change exceeds one of the rise threshold or the fall threshold, generate an alert, (vi) and output a plurality of data alerts. The transmitter controller is configured to (i) perform a beaconing sequence to determine a coupling between the transmitter antenna and the at least one other antenna, (ii) determine the automatic bias control and the automatic gain control, for the demodulation circuit based on the beaconing sequence (iii) receive the plurality of data alerts from the demodulation circuit, and (iv) decode the plurality of data alerts into the wireless data signals.

In a refinement, the demodulation circuit includes a slope detection circuit, and wherein the slope detection circuit comprises a first opamp (operational amplifier) for slope detection to produce a slope detection signal and a second opamp for amplification of the slope detection signal to generate an amplified slope detection signal.

In a further refinement, an offset voltage signal is supplied to the first opamp, the offset voltage signal being controlled by a first digital potentiometer within a first voltage divider, and wherein an amplification control signal is supplied to the second opamp, the amplification control signal being controlled by a second digital potentiometer within a second voltage divider.

In yet a further refinement, respective resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller based on the beaconing sequence.

In yet a further refinement, the beaconing sequence has a maximum beacon voltage and a minimum beacon voltage.

In yet a further refinement, if a coupling between the transmitter antenna and the at least one other antenna is in a minimum coupling range, then the respective resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller based, at least in part, on the maximum beacon voltage.

In yet a further refinement, the resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller as about half of the maximum beacon voltage.

In another further refinement, if a coupling between the transmitter antenna and the at least one other antenna is in a maximum coupling range, then the respective resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller based, at least in part, on the minimum beacon voltage.

In another further refinement, the at least one other system includes a first wireless receiver system and a second wireless receiver system, including, respectively, a first receiver antenna and a second receiver antenna, and the first receiver antenna configured to couple with the transmitter antenna at a first coupling and the second receiver antenna configured to couple with the transmitter antenna at a second coupling.

In yet a further refinement, if the first coupling is within a maximum coupling range and the second coupling is within the maximum coupling range, then the respective resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller based, at least in part, on about 25 percent of the maximum beacon voltage.

In yet another further refinement, if the first coupling is within a minimum coupling range and the second coupling is within a maximum coupling range then the respective resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller based, at least in part, on about half of the maximum beacon voltage.

In yet another further refinement, if the first coupling is within a maximum coupling range and the second coupling is within the maximum coupling range then the respective resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller based, at least in part, on the maximum beacon voltage.

In another further refinement, the transmitter controller sets the respective resistance values of the first digital potentiometer and the second digital potentiometer based on sensed current associated with the wireless data signals and sensed coupling strength between the transmitter antenna and the at least one other antenna.

In a refinement, the electrical characteristics include a voltage of the wireless power signals, and wherein the demodulation circuit is configured to detect a change in the modified electrical information signal by determining a voltage rate of change of the voltage of the modified electrical information.

In a further refinement, the demodulation circuit includes a comparator circuit configured to (i) receive the voltage rate of change, (ii) compare the voltage rate of change to a rising rate of change, and (iii) determine that the change in the electrical characteristics meets or exceeds the rise threshold, if the voltage rate of change meets or exceeds the rising rate of change.

In another further refinement, the demodulation circuit includes a comparator circuit configured to (i) receive the voltage rate of change, (ii) compare the voltage rate of change to a falling rate of change, and (iii) determine that the change in the electrical characteristics meets or exceeds the fall threshold, if the voltage rate of change meets or exceeds the falling rate of change.

In another further refinement, the demodulation circuit includes a comparator circuit configured to (i) receive the voltage rate of change, (ii) compare the voltage rate of change to a rising rate of change, (iii) determine that the change in the electrical characteristics meets or exceeds the rise threshold, if the voltage rate of change meets or exceeds the rising rate of change, (iv) compare the voltage rate of change to a falling rate of change, and (v) determine that the change in the electrical characteristics meets or exceeds the fall threshold, if the voltage rate of change meets or exceeds the falling rate of change.

In yet a further refinement, the demodulation circuit includes a set/reset (SR) latch in operative communication with an output of the comparator circuit.

In a refinement, the transmission antenna is configured to operate based on an operating frequency of about 6.78 MHz.

In accordance with another aspect of the disclosure, a method for automatically controlling gain of a communications signal in a wireless power transmission is disclosed. The wireless power transmission is from a wireless power transmission system to a wireless receiver system and the communications signal is encoded in the wireless power transmission by the wireless receiver system. The method includes performing a beaconing sequence, by the wireless transmission system, to determine presence of the wireless receiver system by detecting a modulated signal within one of at least one power beacon transmitted to the wireless receiver system. The method further includes, if a modulated signal is detected, determining a coupling between a transmitter antenna of the wireless power transmission system and a receiver antenna of the wireless power receiver system, based on the beaconing sequence. The method further includes determining automatic bias control and automatic gain control for a demodulation circuit of the wireless power transmission system, based, at least in part, on the coupling. The method further includes detecting, using at least one sensor, electrical information associated with the electrical characteristics of the wireless power transmission, the electrical information including one or more of a current of the wireless power transmission, a voltage of the wireless power transmission and a power level of the wireless power transmission. The method further includes applying the automatic bias control and automatic gain control to the electrical information to generate a modified electrical information signal. The method further includes determining if the change in the modified electrical information signal meets or exceeds one of a rise threshold and a fall threshold, generating an alert, if the change exceeds one of the rise threshold or the fall threshold, and decoding the alert and subsequent alerts into the communications signal.

These and other aspects and features of the present disclosure will be better understood when read in conjunction with the accompanying drawings.

While the present disclosure is directed to a system that can eliminate certain shortcomings noted in or apparent from this Background section, it should be appreciated that such a benefit is neither a limitation on the scope of the disclosed principles nor of the attached claims, except to the extent expressly noted in the claims. Additionally, the discussion of technology in this Background section is reflective of the inventors' own observations, considerations, and thoughts, and is in no way intended to accurately catalog or comprehensively summarize the art currently in the public domain. As such, the inventors expressly disclaim this section as admitted or assumed prior art. Moreover, the identification herein of a desirable course of action reflects the inventors' own observations and ideas, and should not be assumed to indicate an art-recognized desirability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an embodiment of a system for wirelessly transferring one or more of electrical energy, electrical power signals, electrical power, electromagnetic energy, electronic data, and combinations thereof, in accordance with the present disclosure.

FIG. 2 is a block diagram illustrating components of a wireless transmission system of FIG. 1 and a wireless receiver system of FIG. 1 , in accordance with FIG. 1 and the present disclosure.

FIG. 3 is a block diagram illustrating components of a transmission control system of the wireless transmission system of FIG. 2 , in accordance with FIG. 1 , FIG. 2 , and the present disclosure.

FIG. 4 is a block diagram illustrating components of a sensing system of the transmission control system of FIG. 3 , in accordance with FIGS. 1-3 and the present disclosure.

FIG. 5 is a block diagram of an example low pass filter of the sensing system of FIG. 4 , in accordance with FIGS. 1-4 and the present disclosure.

FIG. 6 is a block diagram illustrating components of a demodulation circuit for the wireless transmission system of FIG. 2 , in accordance with FIGS. 1-5 and the present disclosure.

FIG. 7A is a first portion of a schematic circuit diagram for the demodulation circuit of FIG. 6 in accordance with an embodiment of the present disclosure.

FIG. 7B is a second portion of the schematic circuit diagram for the demodulation circuit of FIGS. 6 and 7A, in accordance with an embodiment of the present disclosure.

FIG. 8 is a timing diagram for voltages of an electrical signal, as it travels through the demodulation circuit, in accordance with FIGS. 1-7 and the present disclosure.

FIG. 9 is a block diagram illustrating components of a power conditioning system of the wireless transmission system of FIG. 2 , in accordance with FIGS. 1-2 , and the present disclosure.

FIG. 10 is a timing plot showing an example beaconing sequence in accordance with an embodiment of the present disclosure.

FIG. 11 is a flow chart showing a process of enabling and disabling beaconing in accordance with an embodiment of the present disclosure.

FIG. 12 is a flow chart showing an example beaconing process to set slope detection bias and gain in accordance with an embodiment of the present disclosure.

FIG. 13 is a block diagram illustrating components of a receiver control system and a receiver power conditioning system of the wireless receiver system of FIGS. 1-2 , in accordance with FIG. 1-2 , and the present disclosure.

FIG. 14 is a top view of a non-limiting, exemplary antenna, for use as a transmitter or receiver antenna of the system of FIGS. 1-13 and/or any other systems, methods, or apparatus disclosed herein, in accordance with the present disclosure.

While the following detailed description will be given with respect to certain illustrative embodiments, it should be understood that the drawings are not necessarily to scale and the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In addition, in certain instances, details which are not necessary for an understanding of the disclosed subject matter or which render other details too difficult to perceive may have been omitted. It should therefore be understood that this disclosure is not limited to the particular embodiments disclosed and illustrated herein, but rather to a fair reading of the entire disclosure and claims, as well as any equivalents thereto. Additional, different, or fewer components and methods may be included in the systems and methods.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

Referring now to the drawings and with specific reference to FIG. 1 , a wireless power transfer system 10 is illustrated. The wireless power transfer system 10 provides for the wireless transmission of electrical signals, such as, but not limited to, electrical energy, electrical power, electrical power signals, electromagnetic energy, and electronically transmittable data (“electronic data”). As used herein, the term “electrical power signal” refers to an electrical signal transmitted specifically to provide meaningful electrical energy for charging and/or directly powering a load, whereas the term “electronic data signal” refers to an electrical signal that is utilized to convey data across a medium.

The wireless power transfer system 10 provides for the wireless transmission of electrical signals via near field magnetic coupling. As shown in the embodiment of FIG. 1 , the wireless power transfer system 10 includes one or more wireless transmission systems 20 and one or more wireless receiver systems 30. A wireless receiver system 30 is configured to receive electrical signals from, at least, a wireless transmission system 20.

As illustrated, the wireless transmission system(s) 20 and wireless receiver system(s) 30 may be configured to transmit electrical signals across, at least, a separation distance or gap 17. A separation distance or gap, such as the gap 17, in the context of a wireless power transfer system, such as the system 10, does not include a physical connection, such as a wired connection. There may be intermediary objects located in a separation distance or gap, such as, but not limited to, air, a counter top, a casing for an electronic device, a plastic filament, an insulator, a mechanical wall, among other things; however, there is no physical, electrical connection at such a separation distance or gap.

Thus, the combination of two or more wireless transmission systems 20 and wireless receiver system 30 create an electrical connection without the need for a physical connection. As used herein, the term “electrical connection” refers to any facilitation of a transfer of an electrical current, voltage, and/or power from a first location, device, component, and/or source to a second location, device, component, and/or destination. An “electrical connection” may be a physical connection, such as, but not limited to, a wire, a trace, a via, among other physical electrical connections, connecting a first location, device, component, and/or source to a second location, device, component, and/or destination. Additionally or alternatively, an “electrical connection” may be a wireless power and/or data transfer, such as, but not limited to, magnetic, electromagnetic, resonant, and/or inductive field, among other wireless power and/or data transfers, connecting a first location, device, component, and/or source to a second location, device, component, and/or destination.

Further, while FIGS. 1-2 may depict wireless power signals and wireless data signals transferring only from one antenna (e.g., a transmission antenna 21) to another antenna (e.g., a receiver antenna 31 and/or a transmission antenna 21), it is certainly possible that a transmitting antenna 21 may transfer electrical signals and/or couple with one or more other antennas and transfer, at least in part, components of the output signals or magnetic fields of the transmitting antenna 21. Such transmission may include secondary and/or stray coupling or signal transfer to multiple antennas of the system 10.

In some cases, the gap 17 may also be referenced as a “Z-Distance,” because, if one considers antennas 21, 31 each to be disposed substantially along respective common X-Y planes, then the distance separating the antennas 21, 31 is the gap in a “Z” or “depth” direction. However, flexible and/or non-planar coils are certainly contemplated by embodiments of the present disclosure and, thus, it is contemplated that the gap 17 may not be uniform, across an envelope of connection distances between the antennas 21, 31. It is contemplated that various tunings, configurations, and/or other parameters may alter the possible maximum distance of the gap 17, such that electrical transmission from the wireless transmission system 20 to the wireless receiver system 30 remains possible. Moreover, in an embodiment, the characteristics of the gap 17 can change during use, such as by an increase or decrease in distance and/or a change in relative device orientations.

The wireless power transfer system 10 operates when the wireless transmission system 20 and the wireless receiver system 30 are coupled. As used herein, the terms “couples,” “coupled,” and “coupling” generally refer to magnetic field coupling, which occurs when a transmitter and/or any components thereof and a receiver and/or any components thereof are coupled to each other through a magnetic field. Such coupling may include coupling, represented by a coupling coefficient (k), that is at least sufficient for an induced electrical power signal, from a transmitter, to be harnessed by a receiver. Coupling of the wireless transmission system 20 and the wireless receiver system 30, in the system 10, may be represented by a resonant coupling coefficient of the system 10 and, for the purposes of wireless power transfer, the coupling coefficient for the system 10 may be in the range of about 0.01 and 0.9.

As illustrated, at least one wireless transmission system 20 is associated with an input power source 12. The input power source 12 may be operatively associated with a host device, which may be any electrically operated device, circuit board, electronic assembly, dedicated charging device, or any other contemplated electronic device. Example host devices, with which the wireless transmission system 20 may be associated therewith, include, but are not limited to including, a device that includes an integrated circuit, a portable computing device, storage medium for electronic devices, charging apparatus for one or multiple electronic devices, dedicated electrical charging devices, among other contemplated electronic devices.

The input power source 12 may be or may include one or more electrical storage devices, such as an electrochemical cell, a battery pack, and/or a capacitor, among other storage devices. Additionally or alternatively, the input power source 12 may be any electrical input source (e.g., any alternating current (AC) or direct current (DC) delivery port) and may include connection apparatus from said electrical input source to the wireless transmission system 20 (e.g., transformers, regulators, conductive conduits, traces, wires, or equipment, goods, computer, camera, mobile phone, and/or other electrical device connection ports and/or adaptors, such as but not limited to USB ports and/or adaptors, among other contemplated electrical components).

Electrical energy received by the wireless transmission system(s) 20 is then used for at least two purposes: to provide electrical power to internal components of the wireless transmission system 20 and to provide electrical power to the transmission antenna 21. The transmission antenna 21 is configured to wirelessly transmit the electrical signals conditioned and modified for wireless transmission by the wireless transmission system 20 via near-field magnetic coupling (NFMC). Near-field magnetic coupling enables the transfer of signals wirelessly through magnetic induction between the transmission antenna 21 and one or more of receiving antenna 31 of, or associated with, the wireless receiver system 30, another transmission antenna 21, or combinations thereof. Near-field magnetic coupling may be and/or be referred to as “inductive coupling,” which, as used herein, is a wireless power transmission technique that utilizes an alternating electromagnetic field to transfer electrical energy between two antennas. Such inductive coupling is the near field wireless transmission of magnetic energy between two magnetically coupled coils that are tuned to resonate at a similar frequency. Accordingly, such near-field magnetic coupling may enable efficient wireless power transmission via resonant transmission of confined magnetic fields. Further, such near-field magnetic coupling may provide connection via “mutual inductance,” which, as defined herein is the production of an electromotive force in a circuit by a change in current in a second circuit magnetically coupled to the first.

In one or more embodiments, the inductor coils of either the transmission antenna 21 or the receiver antenna 31 are strategically positioned to facilitate reception and/or transmission of wirelessly transferred electrical signals through near field magnetic induction. Antenna operating frequencies may comprise relatively high operating frequency ranges, examples of which may include, but are not limited to, 6.78 MHz (e.g., in accordance with the Rezence and/or Airfuel interface standard and/or any other proprietary interface standard operating at a frequency of 6.78 MHz), 13.56 MHz (e.g., in accordance with the NFC standard, defined by ISO/IEC standard 18092), 27 MHz, and/or an operating frequency of another proprietary operating mode. The operating frequencies of the antennas 21, 31 may be operating frequencies designated by the International Telecommunications Union (ITU) in the Industrial, Scientific, and Medical (ISM) frequency bands, including not limited to 6.78 MHz, 13.56 MHz, and 27 MHz, which are designated for use in wireless power transfer.

The transmitting antenna and the receiving antenna of the present disclosure may be configured to transmit and/or receive electrical power having a magnitude that ranges from about 10 milliwatts (mW) to about 500 watts (W). In one or more embodiments the inductor coil of the transmitting antenna 21 is configured to resonate at a transmitting antenna resonant frequency or within a transmitting antenna resonant frequency band.

As known to those skilled in the art, a “resonant frequency” or “resonant frequency band” refers a frequency or frequencies wherein amplitude response of the antenna is at a relative maximum, or, additionally or alternatively, the frequency or frequency band where the capacitive reactance has a magnitude substantially similar to the magnitude of the inductive reactance. In one or more embodiments, the transmitting antenna resonant frequency is at a high frequency, as known to those in the art of wireless power transfer.

The wireless receiver system 30 may be associated with at least one electronic device 14, wherein the electronic device 14 may be any device that requires electrical power for any function and/or for power storage (e.g., via a battery and/or capacitor). Additionally, the electronic device 14 may be any device capable of receipt of electronically transmissible data. For example, the device may be, but is not limited to being, a handheld computing device, a mobile device, a portable appliance, a computer peripheral, an integrated circuit, an identifiable tag, a kitchen utility device, an electronic tool, an electric vehicle, a game console, a robotic device, a wearable electronic device (e.g., an electronic watch, electronically modified glasses, altered-reality (AR) glasses, virtual reality (VR) glasses, among other things), a portable scanning device, a portable identifying device, a sporting good, an embedded sensor, an Internet of Things (IoT) sensor, IoT enabled clothing, IoT enabled recreational equipment, industrial equipment, medical equipment, a medical device a tablet computing device, a portable control device, a remote controller for an electronic device, a gaming controller, among other things.

For the purposes of illustrating the features and characteristics of the disclosed embodiments, arrow-ended lines are utilized to illustrate transferrable and/or communicative signals and various patterns are used to illustrate electrical signals that are intended for power transmission and electrical signals that are intended for the transmission of data and/or control instructions. Solid lines indicate signal transmission of electrical energy over a physical and/or wireless power transfer, in the form of power signals that are, ultimately, utilized in wireless power transmission from the wireless transmission system 20 to the wireless receiver system 30. Further, dotted lines are utilized to illustrate electronically transmittable data signals, which ultimately may be wirelessly transmitted from the wireless transmission system 20 to the wireless receiver system 30.

While the systems and methods herein illustrate the transmission of wirelessly transmitted energy, wireless power signals, wirelessly transmitted power, wirelessly transmitted electromagnetic energy, and/or electronically transmittable data, it is certainly contemplated that the systems, methods, and apparatus disclosed herein may be utilized in the transmission of only one signal, various combinations of two signals, or more than two signals and, further, it is contemplated that the systems, method, and apparatus disclosed herein may be utilized for wireless transmission of other electrical signals in addition to or uniquely in combination with one or more of the above mentioned signals. In some examples, the signal paths of solid or dotted lines may represent a functional signal path, whereas, in practical application, the actual signal is routed through additional components en route to its indicated destination. For example, it may be indicated that a data signal routes from a communications apparatus to another communications apparatus; however, in practical application, the data signal may be routed through an amplifier, then through a transmission antenna, to a receiver antenna, where, on the receiver end, the data signal is decoded by a respective communications device of the receiver.

Turning now to FIGS. 2-3 , the wireless power transfer system 10 is illustrated as a block diagram including example sub-systems of both the wireless transmission systems 20 and the wireless receiver systems 30. The wireless transmission systems 20 may include, at least, a power conditioning system 40, a transmission control system 26, a demodulation circuit 70, a transmission tuning system 24, and the transmission antenna 21. A first portion of the electrical energy input from the input power source 12 may be configured to electrically power components of the wireless transmission system 20 such as, but not limited to, the transmission control system 26.

A second portion of the electrical energy input from the input power source 12 is conditioned and/or modified for wireless power transmission, to the wireless receiver system 30, via the transmission antenna 21. Accordingly, the second portion of the input energy is modified and/or conditioned by the power conditioning system 40. While not illustrated, it is certainly contemplated that one or both of the first and second portions of the input electrical energy may be modified, conditioned, altered, and/or otherwise changed prior to receipt by the power conditioning system 40 and/or transmission control system 26, by further contemplated subsystems (e.g., a voltage regulator, a current regulator, switching systems, fault systems, safety regulators, among other things).

Referring more specifically now to FIG. 3 , with continued reference to FIGS. 1 and 2 , subcomponents and/or systems of the transmission control system 26 are illustrated. The transmission control system 26 may include a sensing system 50, a transmission controller 28, a driver 48, a memory 27 and a demodulation circuit 70.

The transmission controller 28 may be any electronic controller or computing system that includes, at least, a processor which performs operations, executes control algorithms, stores data, retrieves data, gathers data, controls and/or provides communication with other components and/or subsystems associated with the wireless transmission system 20, and/or performs any other computing or controlling task desired. The transmission controller 28 may be a single controller or may include more than one controller disposed to control various functions and/or features of the wireless transmission system 20. Functionality of the transmission controller 28 may be implemented in hardware and/or software and may rely on one or more data maps relating to the operation of the wireless transmission system 20. To that end, the transmission controller 28 may be operatively associated with the memory 27.

The memory may include one or more of internal memory, external memory, and/or remote memory (e.g., a database and/or server operatively connected to the transmission controller 28 via a network, such as, but not limited to, the Internet). The internal memory and/or external memory may include, but are not limited to including, one or more of a read only memory (ROM), including programmable read-only memory (PROM), erasable programmable read-only memory (EPROM or sometimes but rarely labelled EROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), including dynamic RAM (DRAM), static RAM (SRAM), synchronous dynamic RAM (SDRAM), single data rate synchronous dynamic RAM (SDR SDRAM), double data rate synchronous dynamic RAM (DDR SDRAM, DDR2, DDR3, DDR4), and graphics double data rate synchronous dynamic RAM (GDDR SDRAM, GDDR2, GDDR3, GDDR4, GDDR5, a flash memory, a portable memory, and the like. Such memory media are examples of nontransitory machine readable and/or computer readable memory media.

While particular elements of the transmission control system 26 are illustrated as independent components and/or circuits (e.g., the driver 48, the memory 27, the sensing system 50, among other contemplated elements) of the transmission control system 26, such components may be integrated with the transmission controller 28. In some examples, the transmission controller 28 may be an integrated circuit configured to include functional elements of one or both of the transmission controller 28 and the wireless transmission system 20, generally.

As illustrated, the transmission controller 28 is in operative association, for the purposes of data transmission, receipt, and/or communication, with, at least, the memory 27, the power conditioning system 40, the driver 48, and the sensing system 50. The driver 48 may be implemented to control, at least in part, the operation of the power conditioning system 40. In some examples, the driver 48 may receive instructions from the transmission controller 28 to generate and/or output a generated pulse width modulation (PWM) signal to the power conditioning system 40. In some such examples, the PWM signal may be configured to drive the power conditioning system 40 to output electrical power as an alternating current signal, having an operating frequency defined by the PWM signal. In some examples, PWM signal may be configured to generate a duty cycle for the AC power signal output by the power conditioning system 40. In some such examples, the duty cycle may be configured to be about 50% of a given period of the AC power signal.

The sensing system may include one or more sensors, wherein each sensor may be operatively associated with one or more components of the wireless transmission system 20 and configured to provide information and/or data. The term “sensor” is used in its broadest interpretation to define one or more components operatively associated with the wireless transmission system 20 that operate to sense functions, conditions, electrical characteristics, operations, and/or operating characteristics of one or more of the wireless transmission system 20, the wireless receiving system 30, the input power source 12, the host device 11, the transmission antenna 21, the receiver antenna 31, along with any other components and/or subcomponents thereof.

As illustrated in the embodiment of FIG. 4 , the sensing system 50 may include, but is not limited to including, a thermal sensing system 52, an object sensing system 54, a receiver sensing system 56, a current sensor 57, and/or any other sensor(s) 58. Within these systems, there may exist even more specific optional additional or alternative sensing systems addressing particular sensing aspects required by an application, such as, but not limited to: a condition-based maintenance sensing system, a performance optimization sensing system, a state-of-charge sensing system, a temperature management sensing system, a component heating sensing system, an IoT sensing system, an energy and/or power management sensing system, an impact detection sensing system, an electrical status sensing system, a speed detection sensing system, a device health sensing system, among others. The object sensing system 54, may be a foreign object detection (FOD) system.

Each of the thermal sensing system 52, the object sensing system 54, the receiver sensing system 56, the current sensor 57 and/or the other sensor(s) 58, including the optional additional or alternative systems, are operatively and/or communicatively connected to the transmission controller 28. The thermal sensing system 52 is configured to monitor ambient and/or component temperatures within the wireless transmission system 20 or other elements nearby the wireless transmission system 20. The thermal sensing system 52 may be configured to detect a temperature within the wireless transmission system 20 and, if the detected temperature exceeds a threshold temperature, the transmission controller 28 prevents the wireless transmission system 20 from operating. Such a threshold temperature may be configured for safety considerations, operational considerations, efficiency considerations, and/or any combinations thereof. In a non-limiting example, if, via input from the thermal sensing system 52, the transmission controller 28 determines that the temperature within the wireless transmission system 20 has increased from an acceptable operating temperature to an undesired operating temperature (e.g., in a non-limiting example, the internal temperature increasing from about 20° Celsius (C) to about 50° C., the transmission controller 28 prevents the operation of the wireless transmission system 20 and/or reduces levels of power output from the wireless transmission system 20. In some non-limiting examples, the thermal sensing system 52 may include one or more of a thermocouple, a thermistor, a negative temperature coefficient (NTC) resistor, a resistance temperature detector (RTD), and/or any combinations thereof.

As depicted in FIG. 4 , the transmission sensing system 50 may include the object sensing system 54. The object sensing system 54 may be configured to detect one or more of the wireless receiver system 30 and/or the receiver antenna 31, thus indicating to the transmission controller 28 that the receiver system 30 is proximate to the wireless transmission system 20. Additionally or alternatively, the object sensing system 54 may be configured to detect presence of unwanted objects in contact with or proximate to the wireless transmission system 20. In some examples, the object sensing system 54 is configured to detect the presence of an undesired object. In some such examples, if the transmission controller 28, via information provided by the object sensing system 54, detects the presence of an undesired object, then the transmission controller 28 prevents or otherwise modifies operation of the wireless transmission system 20. In some examples, the object sensing system 54 utilizes an impedance change detection scheme, in which the transmission controller 28 analyzes a change in electrical impedance observed by the transmission antenna 20 against a known, acceptable electrical impedance value or range of electrical impedance values.

Additionally or alternatively, the object sensing system 54 may utilize a quality factor (Q) change detection scheme, in which the transmission controller 28 analyzes a change from a known quality factor value or range of quality factor values of the object being detected, such as the receiver antenna 31. The “quality factor” or “Q” of an inductor can be defined as (frequency (Hz)×inductance (H))/resistance (ohms), where frequency is the operational frequency of the circuit, inductance is the inductance output of the inductor and resistance is the combination of the radiative and reactive resistances that are internal to the inductor. “Quality factor,” as defined herein, is generally accepted as an index (figure of measure) that measures the efficiency of an apparatus like an antenna, a circuit, or a resonator. In some examples, the object sensing system 54 may include one or more of an optical sensor, an electro-optical sensor, a Hall Effect sensor, a proximity sensor, and/or any combinations thereof. In some examples, the quality factor measurements, described above, may be performed when the wireless power transfer system 10 is performing in band communications.

The receiver sensing system 56 is any sensor, circuit, and/or combinations thereof configured to detect a presence of any wireless receiving system that may be couplable with the wireless transmission system 20. In some examples, the receiver sensing system 56 and the object sensing system 54 may be combined, may share components, and/or may be embodied by one or more common components. In some examples, if the presence of any such wireless receiving system is detected, wireless transmission of electrical energy, electrical power, electromagnetic energy, and/or data by the wireless transmission system 20 to said wireless receiving system is enabled. In some examples, if the presence of a wireless receiver system is not detected, continued wireless transmission of electrical energy, electrical power, electromagnetic energy, and/or data is prevented from occurring. Accordingly, the receiver sensing system 56 may include one or more sensors and/or may be operatively associated with one or more sensors that are configured to analyze electrical characteristics within an environment of or proximate to the wireless transmission system 20 and, based on the electrical characteristics, determine presence of a wireless receiver system 30.

The current sensor 57 may be any sensor configured to determine electrical information from an electrical signal, such as a voltage or a current, based on a current reading at the current sensor 57. Components of an example current sensor 57 are further illustrated in FIG. 5 , which is a block diagram for the current sensor 57. The current sensor 57 may include a transformer 51, a rectifier 53, and/or a low pass filter 55, to process the AC wireless signals, transferred via coupling between the wireless receiver system(s) 20 and wireless transmission system(s) 30, to determine or provide information to derive a current (I_(Tx)) or voltage (V_(Tx)) at the transmission antenna 21. The transformer 51 may receive the AC wireless signals and either step up or step down the voltage of the AC wireless signal, such that it can properly be processed by the current sensor. The rectifier 53 may receive the transformed AC wireless signal and rectify the signal, such that any negative voltages remaining in the transformed AC wireless signal are either eliminated or converted to opposite positive voltages, to generate a rectified AC wireless signal. The low pass filter 55 is configured to receive the rectified AC wireless signal and filter out AC components (e.g., the operating or carrier frequency of the AC wireless signal) of the rectified AC wireless signal, such that a DC voltage is output for the current (I_(Tx)) and/or voltage (V_(Tx)) at the transmission antenna 21.

FIG. 6 is a block diagram for a demodulation circuit 70 for the wireless transmission system(s) 20, which is used by the wireless transmission system 20 to simplify or decode components of wireless data signals of an alternating current (AC) wireless signal, prior to transmission of the wireless data signal to the transmission controller 28. The demodulation circuit includes, at least, a slope detector 72 and a comparator 74. In some examples, the demodulation circuit 70 includes a set/reset (SR) latch 76.

In some examples, the demodulation circuit 70 may be an analog circuit comprised of one or more passive components (e.g., resistors, capacitors, inductors, diodes, among other passive components) and/or one or more active components (e.g., operational amplifiers, logic gates, among other active components). Alternatively, it is contemplated that the demodulation circuit 70 and some or all of its components may be implemented as an integrated circuit (IC). In either an analog circuit or IC, it is contemplated that the demodulation circuit may be external of the transmission controller 28 and is configured to provide information associated with wireless data signals transmitted from the wireless receiver system 30 to the wireless transmission system 20.

The demodulation circuit 70 is configured to receive electrical information (e.g., I_(Tx), V_(Tx)) from at least one sensor (e.g., a sensor of the sensing system 50), detect a change in such electrical information, determine if the change in the electrical information meets or exceeds one of a rise threshold or a fall threshold. If the change exceeds one of the rise threshold or the fall threshold, the demodulation circuit 70 generates an output signal and also generates and outputs one or more data alerts. Such data alerts are received by the transmitter controller 28 and decoded by the transmitter controller 28 to determine the wireless data signals.

In other words, in an embodiment, the demodulation circuit 70 is configured to monitor the slope of an electrical signal (e.g., slope of a voltage signal at the power conditioning system 32 of a wireless receiver system 30) and to output an indication when said slope exceeds a maximum slope threshold or undershoots a minimum slope threshold. Such slope monitoring and/or slope detection by the communications system 70 is particularly useful when detecting or decoding an amplitude shift keying (ASK) signal that encodes the wireless data signals in-band of the wireless power signal (which is oscillating at the operating frequency).

In an ASK signal, as noted above, the wireless data signals are encoded by damping the voltage of the magnetic field between the wireless transmission system 20 and the wireless receiver system 30. Such damping and subsequent re-rising of the voltage in the field is performed based on an underlying encoding scheme for the wireless data signals (e.g., binary coding, Manchester coding, pulse-width modulated coding, among other known or novel coding systems and methods). The receiver of the wireless data signals (e.g., the wireless transmission system 20 in this example) can then detect rising and falling edges of the voltage of the field and decode said rising and falling edges to demodulate the wireless data signals.

Ideally, an ASK signal would rise and fall instantaneously, with no discernable slope between the high voltage and the low voltage for ASK modulation; however, in reality, there is a finite amount of time that passes when the ASK signal transitions from the “high” voltage to the “low” voltage and vice versa. Thus, the voltage or current signal to be sensed by the demodulation circuit 70 will have some slope or rate of change in voltage when transitioning. By configuring the demodulation circuit 70 to determine when said slope meets, overshoots and/or undershoots such rise and fall thresholds, established based on the known maximum/minimum slope of the carrier signal at the operating frequency, the demodulation circuit can accurately detect rising and falling edges of the ASK signal.

Thus, a relatively inexpensive and/or simplified circuit may be utilized to at least partially decode ASK signals down to notifications or alerts for rising and falling slope instances. As long as the transmission controller 28 is programmed to understand the coding schema of the ASK modulation, the transmission controller 28 will expend far less computational resources than would have been needed to decode the leading and falling edges directly from an input current or voltage sense signal from the sensing system 50. To that end, as the computational resources required by the transmission controller 28 to decode the wireless data signals are significantly decreased due to the inclusion of the demodulation circuit 70, the demodulation circuit 70 may significantly reduce BOM of the wireless transmission system 20, by allowing usage of cheaper, less computationally capable processor(s) for or with the transmission controller 28.

The demodulation circuit 70 may be particularly useful in reducing the computational burden for decoding data signals, at the transmitter controller 28, when the ASK wireless data signals are encoded/decoded utilizing a pulse-width encoded ASK signals, in-band of the wireless power signals. A pulse-width encoded ASK signal is a signal wherein the data is encoded as a percentage of a period of a signal. For example, a two-bit pulse width encoded signal may encode a start bit as 20% of a period between high edges of the signal, encode “1” as 40% of a period between high edges of the signal, and encode “0” as 60% of a period between high edges of the signal, to generate a binary encoding format in the pulse width encoding scheme.

Thus, as the pulse width encoding relies solely on monitoring rising and falling edges of the ASK signal, the periods between rising times need not be constant and the data signals may be asynchronous or “unclocked.” Examples of pulse width encoding and systems and methods to perform such pulse width encoding are explained in greater detail in U.S. patent application Ser. No. 16/735,342 titled “Systems and Methods for Wireless Power Transfer Including Pulse Width Encoded Data Communications,” to Michael Katz, which is commonly owned by the owner of the instant application and is hereby incorporated by reference in its entirety, for all that it teaches without exclusion of any part thereof.

As noted above, slope detection, and hence in-band transfer of data, may become ineffective or inefficient when the signal strength varies from the parameters relied upon during design. For example, when the relative positions of the data sender and data receiver vary significantly during use of the system, the electromagnetic coupling between sender and receiver coils or antennas will also vary. Data detection and decoding are optimized for a particular coupling may fail or underperform at other couplings. As such, a high sensitivity non-saturating detection system is needed to allow the system to operate in environments wherein coupling changes dynamically.

For example, referring to FIG. 7 , the signal created by the high pass filter 71 of the slope detector 72, prior to being amplified by OP_(SD), will vary as a result of varying coupling (as will the power signal, but, for the purposes of the discussion of in-band data, it has now been filtered out at this point). Thus, the difference in magnitude of the amplified signals will vary by even more. At the upper end, substantially improved coupling may cause saturation of OP_(SD), at said upper end, if the system is tuned for small signal detection. Similarly, substantially degraded coupling may result in an undetectable signal if the system is tuned for high, good, and/or fair coupling. Moreover, a pre-amp signal with a positive offset may result in clipped (e.g., saturated) positive signals, post-amplification, unless gain is reduced; however, the reduced gain may in turn render negative signals undetectable. Additionally, a varying load at the receiver may affect the signal, necessitating the amplification of the data signal at the slope detector 72.

As such, instability in coupling is generally not well-tolerated by inductive charging systems, since it causes the filtered and amplified signal to vary too greatly. For example, a phone placed into a fitted dock will stay in a specific location relative to the dock, and any coupling therebetween will remain relatively constant. However, a phone placed on a desktop with an inductive charging station under the desktop may not maintain a fixed relative location, nor a fixed relative orientation and, thus, the range of coupling between the transmitter and the receiver of the phone may vary during the charging process. Further, consider a wireless power system configured for directly powering and/or charging a medical device, while the medical device resides within a human body. Due to natural displacement and/or internal movement of organic elements of the human body, the medical device may not maintain constant location, relative to the body and/or an associated charger positioned outside of the body, and, thus, the transmitter and receiver may couple at a wide range of high, good, fair, low, and/or insufficient coupling levels. Further still, consider a computer peripheral being charged by a charging mat on a user's desk. It may be desired to charge said peripheral, such as a mouse or other input device, during use of the device; such use of the peripheral will necessarily alter coupling during use, as it will be moved regularly, with respect to positioning of the transmitting charging mat.

The effect caused by a difference in the coupling coefficient k can be illustrated by a few non-limiting examples. Consider a case wherein k=0.041, representing fairly strong coupling. In this case, the induced voltage delta (V_(delta)) may be about 160 mV, with the corresponding amplified signal running between a peak of 3.15V and a nadir of 0.45V, for a swing of about 2.70V around a DC offset of 1.86V (i.e., 1.35V above and below the DC offset value).

Now consider a case in the same system wherein a coupling value of 0.01 is exhibited, representing fairly weak coupling. This weakening could happen due to relative movement, intervening materials, or other circumstance. Now V_(delta) may be about 15 mV, with the corresponding amplified signal running between a peak of 1.94V and a nadir of 1.77V, for a swing of about 140 mV around a DC offset of 1.86V (i.e., about 70 mV above and below the DC offset value).

As can be seen from this example, while the strongly coupled case yields robust signals, the weakly coupled case yields very small signals atop a fairly large offset. While perhaps generally detectable, these signal level present a significant risk of data errors and consequently lowered throughput. Moreover, while there is room for increased amplification, the level of amplification, especially given the DC offset, is constrained by the saturation level of the available economical operational amplifier circuits, which, in some examples may be about 4.0V.

However, in an embodiment, automatic gain control in amplification is combined with a voltage offset in slope detection to allow the system to adapt to varying degrees of coupling. This is especially helpful in situations where the physical locations of the coupled devices are not tightly constrained during coupling.

Continuing with the example of FIG. 7 , in the illustrated circuit 72, the bias voltage V′_(Bias) for slope detection is provided by a voltage divider 77 (including linked resistors R_(B1), R_(B2), R_(B3)), which provides a voltage between V_(in) and ground based on a control voltage V_(HB). Given the control voltage V_(HB), the bias voltage V′_(Bias) is set by adjusting a resistance in the voltage divider. In this connection, one of the resistors, e.g., R_(B3), may be a variable resistor, such as a digitally adjustable potentiometer, with the specific resistance being generated via an adaptive bias and gain protocol to be described below, e.g., R_(bias).

Similarly, in the illustrated circuit 72, the output voltage V_(SD) provided to the next stage, comparator 74, is first amplified at a level set by a voltage divider 80 (including linked resistors R_(A1), R_(A2), R_(A3)), based on the control voltage V_(HA) to generate V′_(SD) (slope detection signal). The amplification of V_(SD) to generate V′_(SD) (amplified slope detection signal) is similarly set via a variable potentiometer in the voltage divider, e.g., R_(A1), being set to a specific value, e.g., R_(gain) generated via an adaptive bias and gain protocol to be described later below.

With respect to the aforementioned, non-limiting example, with automatic gain and bias in slope detection, the circuit is configured to accommodate a V_(amp slope delta) of between 400 mv and 2.2V, and a V_(amp DC) offset of between 1.8V and 2.2V. In order to determine appropriate offsets and gains, the system may employ a beaconing sequence state. The beaconing sequence ensures that the transmitter is generally able to detect the receiver at all possible allowed coupling positions and orientations.

Referring still to FIG. 7 , the slope detector 72 includes a high pass filter 71 and an optional stabilizing circuit 73. The high pass filter 71 is configured to monitor for higher frequency components of the AC wireless signals and may include, at least, a filter capacitor (C_(HF)) and a filter resistor (R_(HF)). The values for C_(HF) and R_(HF) are selected and/or tuned for a desired cutoff frequency for the high pass filter 71. In some examples, the cutoff frequency for the high pass filter 71 may be selected as a value greater than or equal to about 1-2 kHz, to ensure adequately fast slope detection by the slope detector 72, when the operating frequency of the system 10 is on the order of MHz (e.g., an operating frequency of about 6.78 MHz). In some examples, the high pass filter 71 is configured such that harmonic components of the detected slope are unfiltered. In view of the current sensor 57 of FIG. 5 , the high pass filter 71 and the low pass filter 55, in combination, may function as a bandpass filter for the demodulation circuit 70.

OP_(SD) is any operational amplifier having an adequate bandwidth for proper signal response, for outputting the slope of V_(Tx), but low enough to attenuate components of the signal that are based on the operating frequency and/or harmonics of the operating frequency. Additionally or alternatively, OP_(SD) may be selected to have a small input voltage range for V_(Tx), such that OP_(SD) may avoid unnecessary error or clipping during large changes in voltage at V_(Tx). Further, an input bias voltage (V_(Bias)) for OP_(SD) may be selected based on values that ensure OP_(SD) will not saturate under boundary conditions (e.g., steepest slopes, largest changes in V_(Tx)). It is to be noted, and is illustrated in Plot B of FIG. 8 , that when no slope is detected, the output of the slope detector 72 will be V_(Bias).

As the passive components of the slope detector 72 will set the terminals and zeroes for a transfer function of the slope detector 72, such passive components must be selected to ensure stability. To that end, if the desired and/or available components selected for C_(HF) and R_(HF) do not adequately set the terminals and zeros for the transfer function, additional, optional stability capacitor(s) C_(ST) may be placed in parallel with R_(HF) and stability resistor R_(ST) may be placed in the input path to OP_(SD).

Output of the slope detector 72 (Plot B representing V_(SD)) may approximate the following equation:

$V_{SD} = {{{- R_{HF}}C_{HF}\frac{dV}{dt}} + V_{Bias}}$

Thus, V_(SD) will approximate to V_(Bias), when no change in voltage (slope) is detected, and Output V_(SD) of the slope detector 72 is represented in Plot B. As can be seen, the value of V_(SD) approximates V_(Bias) when no change in voltage (slope) is detected, whereas V_(SD) will output the change in voltage (dV/dt), as scaled by the high pass filter 71, when V_(Tx) rises and falls between the high voltage and the low voltage of the ASK modulation. The output of the slope detector 72, as illustrated in Plot B, may be a pulse, showing slope of V_(Tx) rise and fall.

V_(SD) is output to the comparator circuit(s) 74, which is configured to receive V_(SD), compare V_(SD) to a rising rate of change for the voltage (V_(SUp)) and a falling rate of change for the voltage (V_(SLo)). If V_(SD) exceeds or meets V_(SUp), then the comparator circuit will determine that the change in V_(Tx) meets the rise threshold and indicates a rising edge in the ASK modulation. If V_(SD) goes below or meets V_(SLow), then the comparator circuit will determine that the change in V_(Tx) meets the fall threshold and indicates a falling edge of the ASK modulation. It is to be noted that V_(SUp) and V_(SLo) may be selected to ensure a symmetrical triggering.

FIG. 8 is an exemplary timing diagram illustrating signal shape or waveform at various stages or sub-circuits of the demodulation circuit 70. The input signal to the demodulation circuit 70 is illustrated in FIG. 8 as Plot A, showing rising and falling edges from a “high” voltage (V_(High)) perturbation on the transmission antenna 21 to a “low” voltage (V_(Low)) perturbation on the transmission antenna 21. The voltage signal of Plot A may be derived from, for example, a current (I_(Tx)) sensed at the transmission antenna 21 by one or more sensors of the sensing system 50. Such rises and falls from V_(High) to V_(Low) may be caused by load modulation, performed at the wireless receiver system(s) 30, to modulate the wireless power signals to include the wireless data signals via ASK modulation. As illustrated, the voltage of Plot A does not cleanly rise and fall when the ASK modulation is performed; rather, a slope or slopes, indicating rate(s) of change, occur during the transitions from V_(High) to V_(Low) and vice versa.

As illustrated in FIG. 7 , the slope detector 72 includes a high pass filter 71, an operation amplifier (OpAmp) OP_(SD), and an optional stabilizing circuit 73. The high pass filter 71 is configured to monitor for higher frequency components of the AC wireless signals and may include, at least, a filter capacitor (C_(HF)) and a filter resistor (R_(HF)). The values for C_(HF) and R_(HF) are selected and/or tuned for a desired cutoff frequency for the high pass filter 71. In some examples, the cutoff frequency for the high pass filter 71 may be selected as a value greater than or equal to about 1-2 kHz, to ensure adequately fast slope detection by the slope detector 72, when the operating frequency of the system 10 is on the order of MHz (e.g., an operating frequency of about 6.78 MHz). In some examples, the high pass filter 71 is configured such that harmonic components of the detected slope are unfiltered. In view of the current sensor 57 of FIG. 5 , the high pass filter 71 and the low pass filter 55, in combination, may function as a bandpass filter for the demodulation circuit 70.

OP_(SD) is any operational amplifier having an adequate bandwidth for proper signal response, for outputting the slope of V_(Tx), but low enough to attenuate components of the signal that are based on the operating frequency and/or harmonics of the operating frequency. Additionally or alternatively, OP_(SD) may be selected to have a small input voltage range for V_(Tx), such that OP_(SD) may avoid unnecessary error or clipping during large changes in voltage at V_(Tx). Further, an input bias voltage (V_(Bias)) for OP_(SD) may be selected based on values that ensure OP_(SD) will not saturate under boundary conditions (e.g., steepest slopes, largest changes in V_(Tx)). It is to be noted, and is illustrated in Plot B of FIG. 8 , that when no slope is detected, the output of the slope detector 72 will be V_(Bias).

As the passive components of the slope detector 72 will set the terminals and zeroes for a transfer function of the slope detector 72, such passive components must be selected to ensure stability. To that end, if the desired and/or available components selected for C_(HF) and R_(HF) do not adequately set the terminals and zeros for the transfer function, additional, optional stability capacitor(s) C_(ST) may be placed in parallel with R_(HF) and stability resistor R_(ST) may be placed in the input path to OP_(SD).

Output of the slope detector 72 (Plot B representing V_(SD)) may approximate the following equation:

$V_{SD} = {{{- R_{HF}}C_{HF}\frac{dV}{dt}} + V_{Bias}}$

Thus, V_(SD) will approximate to V_(Bias), when no change in voltage (slope) is detected, and output V_(SD) of the slope detector 72 is represented in Plot B. As can be seen, the value of V_(SD) approximates V_(Bias) when no change in voltage (slope) is detected, whereas V_(SD) will output the change in voltage (dV/dt), as scaled by the high pass filter 71, when V_(Tx) rises and falls between the high voltage and the low voltage of the ASK modulation. The output of the slope detector 72, as illustrated in Plot B, may be a pulse, showing slope of V_(Tx) rise and fall.

V_(SD) is output to the comparator circuit(s) 74, which is configured to receive V_(SD), compare V_(SD) to a rising rate of change for the voltage (V_(SUp)) and a falling rate of change for the voltage (V_(SLo)). If V_(SD) exceeds or meets V_(SUp), then the comparator circuit will determine that the change in V_(Tx) meets the rise threshold and indicates a rising edge in the ASK modulation. If V_(SD) goes below or meets V_(SLow), then the comparator circuit will determine that the change in V_(Tx) meets the fall threshold and indicates a falling edge of the ASK modulation. It is to be noted that V_(SUp) and V_(SLo) may be selected to ensure a symmetrical triggering.

In some examples, such as the comparator circuit 74 illustrated in FIG. 6 , the comparator circuit 74 may comprise a window comparator circuit. In such examples, the V_(SUp) and V_(SLo) may be set as a fraction of the power supply determined by resistor values of the comparator circuit 74. In some such examples, resistor values in the comparator circuit may be configured such that

${V_{Sup} = {V_{in}\left\lbrack \frac{R_{U2}}{R_{U1} + R_{U2}} \right\rbrack}}{V_{SLo} = {V_{in}\left\lbrack \frac{R_{L2}}{R_{L1} + R_{L2}} \right\rbrack}}$ where Vin is a power supply determined by the comparator circuit 74. When V_(SD) exceeds the set limits for V_(Sup) or V_(SLo), the comparator circuit 74 triggers and pulls the output (V_(Cout)) low.

Further, while the output of the comparator circuit 74 could be output to the transmission controller 28 and utilized to decode the wireless data signals by signaling the rising and falling edges of the ASK modulation, in some examples, the SR latch 76 may be included to add noise reduction and/or a filtering mechanism for the slope detector 72. The SR latch 76 may be configured to latch the signal (Plot C) in a steady state to be read by the transmitter controller 28, until a reset is performed. In some examples, the SR latch 76 may perform functions of latching the comparator signal and serve as an inverter to create an active high alert out signal. Accordingly, the SR latch 76 may be any SR latch known in the art configured to sequentially excite when the system detects a slope or other modulation excitation. As illustrated, the SR latch 76 may include NOR gates, wherein such NOR gates may be configured to have an adequate propagation delay for the signal. For example, the SR latch 76 may include two NOR gates (NOR_(Up), NOR_(Lo)), each NOR gate operatively associated with the upper voltage output 78 of the comparator 74 and the lower voltage output 79 of the comparator 74.

In some examples, such as those illustrated in Plot C, a reset of the SR latch 76 is triggered when the comparator circuit 74 outputs detection of V_(SUp) (solid plot on Plot C) and a set of the SR latch 76 is triggered when the comparator circuit 74 outputs V_(SLo) (dashed plot on Plot C). Thus, the reset of the SR latch 76 indicates a falling edge of the ASK modulation and the set of the SR latch 76 indicates a rising edge of the ASK modulation. Accordingly, as illustrated in Plot D, the rising and falling edges, indicated by the demodulation circuit 70, are input to the transmission controller 28 as alerts, which are decoded to determine the received wireless data signal transmitted, via the ASK modulation, from the wireless receiver system(s) 30.

The incoming signal VTX exemplified in the plots of FIG. 8 does not lead to excess bias or saturation because the values of V_(BIAS) and V_(G) are at appropriate levels, but the coupling environment may change (e.g., from strong to weak coupling), such that the existing V_(BIAS) and V_(G) are no longer appropriate and would no longer allow accurate signal detection. However, automatic gain and bias routines are applied as described herein to continually evaluate the system behavior and set V_(BIAS) and V_(G) such that accurate signal detection is provided throughout the range of allowable coupling strengths.

Referring now to FIG. 9 , and with continued reference to FIGS. 1-4 , a block diagram illustrating an embodiment of the power conditioning system 40 is illustrated. At the power conditioning system 40, electrical power is received, generally, as a DC power source, via the input power source 12 itself or an intervening power converter, converting an AC source to a DC source (not shown). A voltage regulator 46 receives the electrical power from the input power source 12 and is configured to provide electrical power for transmission by the antenna 21 and provide electrical power for powering components of the wireless transmission system 21. Accordingly, the voltage regulator 46 is configured to convert the received electrical power into at least two electrical power signals, each at a proper voltage for operation of the respective downstream components: a first electrical power signal to electrically power any components of the wireless transmission system 20 and a second portion conditioned and modified for wireless transmission to the wireless receiver system 30. As illustrated in FIG. 3 , such a first portion is transmitted to, at least, the sensing system 50, the transmission controller 28, and the communications system 29; however, the first portion is not limited to transmission to just these components and can be transmitted to any electrical components of the wireless transmission system 20.

The second portion of the electrical power is provided to an amplifier 42 of the power conditioning system 40, which is configured to condition the electrical power for wireless transmission by the antenna 21. The amplifier may function as an inverter, which receives an input DC power signal from the voltage regulator 46 and generates an AC as output, based, at least in part, on PWM input from the transmission control system 26. The amplifier 42 may be or include, for example, a power stage invertor, such as a single field effect transistor (FET), a dual field effect transistor power stage invertor or a quadruple field effect transistor power stage invertor. The use of the amplifier 42 within the power conditioning system 40 and, in turn, the wireless transmission system 20 enables wireless transmission of electrical signals having much greater amplitudes than if transmitted without such an amplifier. For example, the addition of the amplifier 42 may enable the wireless transmission system 20 to transmit electrical energy as an electrical power signal having electrical power from about 10 mW to about 500 W. In some examples, the amplifier 42 may be or may include one or more class-E power amplifiers. Class-E power amplifiers are efficiently tuned switching power amplifiers designed for use at high frequencies (e.g., frequencies from about 1 MHz to about 1 GHz). Generally, a single-ended class-E amplifier employs a single-terminal switching element and a tuned reactive network between the switch and an output load (e.g., the antenna 21). Class E amplifiers may achieve high efficiency at high frequencies by only operating the switching element at points of zero current (e.g., on-to-off switching) or zero voltage (off to on switching). Such switching characteristics may minimize power lost in the switch, even when the switching time of the device is long compared to the frequency of operation. However, the amplifier 42 is certainly not limited to being a class-E power amplifier and may be or may include one or more of a class D amplifier, a class EF amplifier, an H invertor amplifier, and/or a push-pull invertor, among other amplifiers that could be included as part of the amplifier 42.

Although the precise manner of beaconing is not essential, an example “staircase” beaconing protocol is illustrated in FIG. 10 , which may be used as an initial beaconing process by the transmission controller 28. As can be seen, the wireless transmission system 20 sends beacons of power at different power levels 901, 903, 905 searching for the receiver, which may be located and oriented such as to yield a high coupling, a low coupling or a moderate coupling. Thus, each of a plurality of beacons of power (e.g., 901, 903, 905) may be configured to detect a wireless receiver system 30 at one of a range of couplings between the antennas 21, 31. More specifically, the plurality of beacons of power may include one or more of a beacon for detecting a high coupling between the antennas 21, 31, a beacon for detecting a moderate coupling between the antennas 21, 31, and/or a beacon for detecting a low coupling between the antennas 21, 31. It will be appreciated that the entire beaconing sequence need not be executed, e.g., when the receiver is detected early in the process.

In the illustrated example, the beaconing power of each level 901, 903, 905 is set as a fraction of a voltage for input to the amplifier 42 (V_(pa)) including Vpa_(B1), Vpa_(B2) and Vpa_(B3), with each beaconing level being employed for a level period t_(bLevelPeriod) (907), and with the entire multi-level sequence taking a time t_(bTotalPeriod) (909) to execute. The term “V_(pa),” as discussed with respect to FIGS. 10-12 , refers to a maximum voltage input to the amplifier 42, during the beaconing sequence(s). Such voltages may be provided to the amplifier 42 by the transmission controller 42 as amplifier voltage instructions that are based on the initial beaconing process, to be provided along with driving signals based on, at least, the operating frequency and the initial beaconing process.

While three evenly-distributed non-zero beacon levels are illustrated for simplicity of illustration and understanding, it will be appreciated that a larger number of evenly-distributed levels (e.g., 12 levels) is preferable for granularity, within the allowable range, having a maximum beaconed V_(pa). Moreover, in an embodiment, t_(bTotalPeriod) and t_(bLevelPeriod) are selected to be as small as is practicable to minimize idle power. Although the illustrated beacon power levels 901, 903, 905 are evenly-spaced, it will be appreciated that there is no requirement for even spacing within the disclosed principles.

During the beaconing sequence, V_(pa) can be used to provide an initial estimate for the required offset and gain for the automatic gain control of the demodulation circuit 70. In an embodiment, the transfer function for gain and offset based on V_(pa) are: Rgain=a*V _(pa) +b Rbias=c*V _(pa) +d where a, b, c, and d are constants tuned for the specific system. Rgain is the set resistance for the second voltage divider 80 and Rbias is the set resistance for the first voltage divider 77.

After beaconing to locate the receiver, the gain and offset may be further fine-tuned away from the above values by the transmitter to optimize in-band signaling by sensing a change in coupled current (Itx_sense_delta) for each beaconing power level 901, 903, 905 and setting the gain and bias based on Itx_sense_delta as follows: Rgain=e*Itx_sense_delta+f Rbias=g*Itx_sense_delta+h Where e, f g and h are constants tuned for the specific system.

It will be appreciated that beaconing as described above generally takes place prior to other communications between the particular transmitter and receiver, but may also occur after communications are lost following a period of successful communication. In an embodiment, the beaconing sequence state is activated and deactivated according to the process 2600 shown in the flow chart of FIG. 11 . It will be appreciated that the process 2600 and other process flows illustrated herein may be executed by a transmission or receiver controller 28, 38 or by another processing entity.

At stage 2601 of the process 2600, Rgain and Rbias are set in accordance with the first power level, which in the above example is Vpa_(B1). The amplifier 42 voltage is set in stage 2603 and the amplifier 42 is enabled at stage 2605. Finally, the operating frequency, e.g., 6.78 Mhz, is enabled on a gate of the amplifier 42 at stage 2607. The beaconing sequence state is then executed in stage 2609.

After the beaconing sequence state is executed, a beaconing sequence state shut down process is executed starting at stage 2611, wherein the operating frequency is disabled on the gate of the amplifier 42. The amplifier 42 is disabled at stage 2613, and Rgain and Rbias are set to values corresponding to Vpa_(B1) at stage 2615. Finally, at stage 2617 the amplifier 42 voltage is set to the beacons mode level.

While process 2600 of FIG. 11 illustrates the enabling and disabling of the beaconing sequence process, the process 2700 of FIG. 12 focuses on the beaconing sequence process itself as well as the subsequent gain and bias refining process. As noted above, beaconing in this context employs increasing transmit power levels to elicit a response from a nearby receiving device (e.g., the wireless receiver system 30). Once the nearby device is reached, the process switches to a refinement process to optimize the slope detector gain and offset for best signal detectability.

Turning then to FIG. 12 in more detail, the process 2700, which may be executed by the transmitter controller 28 and utilize other aspects of the wireless transmission system 20, starts at stage 2701 with the enabling of the beaconing sequence state. Once within the beaconing sequence state, and executing the stepped beaconing protocol, the process 2700 moves to stage 2703, wherein it is determined whether a valid modulated signal has been detected, as received from the wireless transmission system 30. If a valid modulated signal has been detected, then the process flows to stage 2709, which will be described below. If instead, a valid modulated signal has not been detected, then the process 2700 flows to stage 2705, wherein it is determined whether an impedance change within the current range has been detected. If such an impedance change has been detected, the process 2700 flows to stage 2707, wherein it enters an extended beacon state. Otherwise, an error may be declared, and the system may continue back to stage 2707, wherein another extended beacon state is beaconed. Stage 2707 may be repeated, if no modulated signal is detected, for any number of beacons of the beaconing protocol, such as the three states illustrated in FIG. 10 , 12 stages, as discussed above, and/or any number of beaconing states desired for a given system and/or beaconing protocol.

In the extended beacon state of stage 2707, if a valid modulated signal is detected, the process 2700 flows to stage 2709. In stages 2709-2717, new estimates for gain and bias are used to maximize demodulation gain without saturation. In particular, as noted above, Rgain and Rbias are assumed to be linearly related, with respect to Itx_sense_delta, with appropriate scale and offset constants.

At stage 2709, if there is one receiver in a maximum detectable coupling range (Max K) (not necessarily a maximum, but within a highest range of coupling), then Vpa is adjusted to the minimum beaconing range. From stage 2709, the process continues to stage 2711, wherein if there are two receivers at Max K, then “Vpa,” as used in the relationships for setting initial Rgain, Rbias is increased to 25% the maximum Vpa. At stage 2713, if there is one receiver in a minimum detectable coupling range (Min K) (not necessarily a minimum, but within a lowest range of K), then Vpa for setting initial Rgain, Rbias is increased to 50% of the maximum Vpa. If there is one receiver at Min K and one receiver at Max K, then at stage 2715, Vpa for setting initial Rgain, Rbias is increased to 75% of the maximum Vpa. Finally, at stage 2717, if there are two receivers at Max K, then Vpa is increased to its maximum allowed value. Then, Rgain and Rbias are set for optimal signal demodulation and the system proceeds with sending power signals to the receiver system 30 and/or receiving data communications from the receiver system 30.

In this way, the values for Rgain and Rbias are adjusted so as to achieve good signal detection without risking saturation of system components such as the slope detection signal amplification elements. While the processes described above may be carried out by any appropriate processing entity, the resulting values are implemented in an appropriate slope detection circuit. Once adequate and non-saturating slope detection and amplification are achieved, the amplified slope changes can then be processed via quantification (e.g., via one or more comparators) and reconstruction (e.g., via latching) as indicated above to produce a data signal for interpretation.

Turning now to FIG. 13 and with continued reference to, at least, FIGS. 1 and 2 , the wireless receiver system 30 is illustrated in further detail. The wireless receiver system 30 is configured to receive, at least, electrical energy, electrical power, electromagnetic energy, and/or electrically transmittable data via near field magnetic coupling from the wireless transmission system 20, via the transmission antenna 21. As illustrated in FIG. 9 , the wireless receiver system 30 includes, at least, the receiver antenna 31, a receiver tuning and filtering system 34, a power conditioning system 32, a receiver control system 36, and a voltage isolation circuit 70. The receiver tuning and filtering system 34 may be configured to substantially match the electrical impedance of the wireless transmission system 20. In some examples, the receiver tuning and filtering system 34 may be configured to dynamically adjust and substantially match the electrical impedance of the receiver antenna 31 to a characteristic impedance of the power generator or the load at a driving frequency of the transmission antenna 20.

As illustrated, the power conditioning system 32 includes a rectifier 33 and a voltage regulator 35. In some examples, the rectifier 33 is in electrical connection with the receiver tuning and filtering system 34. The rectifier 33 is configured to modify the received electrical energy from an alternating current electrical energy signal to a direct current electrical energy signal. In some examples, the rectifier 33 is comprised of at least one diode. Some non-limiting example configurations for the rectifier 33 include, but are not limited to including, a full wave rectifier, including a center tapped full wave rectifier and a full wave rectifier with filter, a half wave rectifier, including a half wave rectifier with filter, a bridge rectifier, including a bridge rectifier with filter, a split supply rectifier, a single phase rectifier, a three phase rectifier, a voltage doubler, a synchronous voltage rectifier, a controlled rectifier, an uncontrolled rectifier, and a half controlled rectifier. As electronic devices may be sensitive to voltage, additional protection of the electronic device may be provided by clipper circuits or devices. In this respect, the rectifier 33 may further include a clipper circuit or a clipper device, which is a circuit or device that removes either the positive half (top half), the negative half (bottom half), or both the positive and the negative halves of an input AC signal. In other words, a clipper is a circuit or device that limits the positive amplitude, the negative amplitude, or both the positive and the negative amplitudes of the input AC signal.

Some non-limiting examples of a voltage regulator 35 include, but are not limited to, including a series linear voltage regulator, a buck convertor, a low dropout (LDO) regulator, a shunt linear voltage regulator, a step up switching voltage regulator, a step down switching voltage regulator, an inverter voltage regulator, a Zener controlled transistor series voltage regulator, a charge pump regulator, and an emitter follower voltage regulator. The voltage regulator 35 may further include a voltage multiplier, which is as an electronic circuit or device that delivers an output voltage having an amplitude (peak value) that is two, three, or more times greater than the amplitude (peak value) of the input voltage. The voltage regulator 35 is in electrical connection with the rectifier 33 and configured to adjust the amplitude of the electrical voltage of the wirelessly received electrical energy signal, after conversion to AC by the rectifier 33. In some examples, the voltage regulator 35 may an LDO linear voltage regulator; however, other voltage regulation circuits and/or systems are contemplated. As illustrated, the direct current electrical energy signal output by the voltage regulator 35 is received at the load 16 of the electronic device 14. In some examples, a portion of the direct current electrical power signal may be utilized to power the receiver control system 36 and any components thereof; however, it is certainly possible that the receiver control system 36, and any components thereof, may be powered and/or receive signals from the load 16 (e.g., when the load 16 is a battery and/or other power source) and/or other components of the electronic device 14.

The receiver control system 36 may include, but is not limited to including, a receiver controller 38, a communications system 39 and a memory 37. The receiver controller 38 may be any electronic controller or computing system that includes, at least, a processor which performs operations, executes control algorithms, stores data, retrieves data, gathers data, controls and/or provides communication with other components and/or subsystems associated with the wireless receiver system 30. The receiver controller 38 may be a single controller or may include more than one controller disposed to control various functions and/or features of the wireless receiver system 30. Functionality of the receiver controller 38 may be implemented in hardware and/or software and may rely on one or more data maps relating to the operation of the wireless receiver system 30. To that end, the receiver controller 38 may be operatively associated with the memory 37. The memory may include one or both of internal memory, external memory, and/or remote memory (e.g., a database and/or server operatively connected to the receiver controller 38 via a network, such as, but not limited to, the Internet). The internal memory and/or external memory may include, but are not limited to including, one or more of a read only memory (ROM), including programmable read-only memory (PROM), erasable programmable read-only memory (EPROM or sometimes but rarely labelled EROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), including dynamic RAM (DRAM), static RAM (SRAM), synchronous dynamic RAM (SDRAM), single data rate synchronous dynamic RAM (SDR SDRAM), double data rate synchronous dynamic RAM (DDR SDRAM, DDR2, DDR3, DDR4), and graphics double data rate synchronous dynamic RAM (GDDR SDRAM, GDDR2, GDDR3, GDDR4, GDDR5), a flash memory, a portable memory, and the like. Such memory media are examples of nontransitory computer readable memory media.

Further, while particular elements of the receiver control system 36 are illustrated as subcomponents and/or circuits (e.g., the memory 37, the communications system 39, among other contemplated elements) of the receiver control system 36, such components may be external of the receiver controller 38. In some examples, the receiver controller 38 may be and/or include one or more integrated circuits configured to include functional elements of one or both of the receiver controller 38 and the wireless receiver system 30, generally. As used herein, the term “integrated circuits” generally refers to a circuit in which all or some of the circuit elements are inseparably associated and electrically interconnected so that it is considered to be indivisible for the purposes of construction and commerce. Such integrated circuits may include, but are not limited to including, thin-film transistors, thick-film technologies, and/or hybrid integrated circuits.

FIG. 14 illustrates an example, non-limiting embodiment of one or both of the transmitter antenna 21 and/or the receiver antenna 31 that may be used with any of the systems, methods, and/or apparatus disclosed herein. In the illustrated embodiment, the antenna 21, 31, is a flat spiral coil configuration. Non-limiting examples can be found in U.S. Pat. Nos. 9,941,743, 9,960,628, 9,941,743 all to Peralta et al.; U.S. Pat. Nos. 9,948,129, 10,063,100 to Singh et al.; U.S. Pat. No. 9,941,590 to Luzinski; U.S. Pat. No. 9,960,629 to Rajagopalan et al.; and U.S. Patent App. Nos. 2017/0040107, 2017/0040105, 2017/0040688 to Peralta et al.; all of which are assigned to the assignee of the present application and incorporated fully herein by reference.

In addition, the antenna 21, 31 may be constructed having a multi-layer-multi-turn (MLMT) construction in which at least one insulator is positioned between a plurality of conductors. Non-limiting examples of antennas having an MLMT construction that may be incorporated within the wireless transmission system(s) 20 and/or the wireless receiver system(s) 30 may be found in U.S. Pat. Nos. 8,610,530, 8,653,927, 8,680,960, 8,692,641, 8,692,642, 8,698,590, 8,698,591, 8,707,546, 8,710,948, 8,803,649, 8,823,481, 8,823,482, 8,855,786, 8,898,885, 9,208,942, 9,232,893, and 9,300,046 to Singh et al., all of which are assigned to the assignee of the present application are incorporated fully herein. These are merely exemplary antenna examples; however, it is contemplated that the antennas 31 may be any antenna capable of the aforementioned higher power, high frequency wireless power transfer.

The automatic gain and bias control described herein may significantly reduce the BOM for the demodulation circuit, and the wireless transmission system as a whole, by allowing usage of cheaper, less computationally capable processor(s) for or with the transmission controller. The throughput and accuracy of an edge-detection coding scheme depends in large part upon the system's ability to quickly and accurately detect signal slope changes. These constraints may be better met in environments wherein the distance between, and orientations of, the sender and receiver change dynamically, or the magnitude of the received power signal and embedded data signal may change dynamically, via the disclosed automatic gain and bias control. This may allow reading of faint signals via appropriate gain, for example, while also avoiding saturation with respect to larger signals.

The systems, methods, and apparatus disclosed herein are designed to operate in an efficient, stable and reliable manner to satisfy a variety of operating and environmental conditions. The systems, methods, and/or apparatus disclosed herein are designed to operate in a wide range of thermal and mechanical stress environments so that data and/or electrical energy is transmitted efficiently and with minimal loss. In addition, the system 10 may be designed with a small form factor using a fabrication technology that allows for scalability, and at a cost that is amenable to developers and adopters. In addition, the systems, methods, and apparatus disclosed herein may be designed to operate over a wide range of frequencies to meet the requirements of a wide range of applications.

In an embodiment, a ferrite shield may be incorporated within the antenna structure to improve antenna performance. Selection of the ferrite shield material may be dependent on the operating frequency as the complex magnetic permeability (μ=μ′−j*μ″) is frequency dependent. The material may be a polymer, a sintered flexible ferrite sheet, a rigid shield, or a hybrid shield, wherein the hybrid shield comprises a rigid portion and a flexible portion. Additionally, the magnetic shield may be composed of varying material compositions. Examples of materials may include, but are not limited to, zinc comprising ferrite materials such as manganese-zinc, nickel-zinc, copper-zinc, magnesium-zinc, and combinations thereof.

As used herein, the phrase “at least one of” preceding a series of items, with the term “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list (i.e., each item). The phrase “at least one of” does not require selection of at least one of each item listed; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or at least one of each of A, B, and C.

The predicate words “configured to”, “operable to”, and “programmed to” do not imply any particular tangible or intangible modification of a subject, but, rather, are intended to be used interchangeably. In one or more embodiments, a processor configured to monitor and control an operation or a component may also mean the processor being programmed to monitor and control the operation or the processor being operable to monitor and control the operation. Likewise, a processor configured to execute code can be construed as a processor programmed to execute code or operable to execute code.

A phrase such as “an aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. An aspect may provide one or more examples of the disclosure. A phrase such as an “aspect” may refer to one or more aspects and vice versa. A phrase such as an “embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. An embodiment may provide one or more examples of the disclosure. A phrase such an “embodiment” may refer to one or more embodiments and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A configuration may provide one or more examples of the disclosure. A phrase such as a “configuration” may refer to one or more configurations and vice versa.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” or as an “example” is not necessarily to be construed as preferred or advantageous over other embodiments. Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim.

All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”

Reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the subject disclosure.

While this specification contains many specifics, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of particular implementations of the subject matter. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination. 

The invention claimed is:
 1. A wireless power transfer system comprising: a medical device comprising a wireless power receiver system including a receiver antenna; and a wireless power transmission system including: a transmitter antenna configured to couple with the receiver antenna of the medical device and transmit alternating current (AC) wireless signals to the receiver antenna, the AC wireless signals including wireless power signals and wireless data signals, the wireless data signals generated by altering electrical characteristics of the AC wireless signals at the receiver antenna; an amplifier that is configured to receive a driving signal at a gate of at least one transistor and invert a direct power (DC) input power signal to generate the AC wireless signals at an operating frequency; at least one sensor configured to detect electrical information associated with the electrical characteristics of the AC wireless signals, the electrical information including one or more of a current of the AC wireless signals, a voltage of the AC wireless signals, or a power level of the AC wireless signals; a demodulation circuit configured to (i) receive the electrical information from the at least one sensor, (ii) apply automatic bias control and gain control to the electrical information to generate a modified electrical information signal (iii) detect a change in the modified electrical information signal, (iv) determine if the change in the modified electrical information signal meets or exceeds one of a rise threshold or a fall threshold, (v) if the change exceeds one of the rise threshold or the fall threshold, generate an alert, (vi) and output a plurality of data alerts, wherein the demodulation circuit includes a slope detection circuit, and wherein the slope detection circuit comprises a first operational amplifier (opamp) for slope detection to produce a slope detection signal and a second opamp for amplification of the slope detection signal to generate an amplified slope detection signal and wherein an offset voltage signal is supplied to the first opamp, the offset voltage signal being controlled by a first digital potentiometer within a first voltage divider, and wherein an amplification control signal is supplied to the second opamp, the amplification control signal being controlled by a second digital potentiometer within a second voltage divider; and a transmitter controller configured to (i) configure the driving signal based, at least, on an operating frequency and an initial beaconing process, the initial beaconing process for determining presence of the wireless power receiver system at a coupling between the transmitter antenna and a receiver antenna of the wireless power receiver system, (ii) determine amplifier voltage instructions for the amplifier based on the initial beaconing process, (iii) drive the amplifier by providing the driving signal and the amplifier voltage instructions to the amplifier, (iv) receive the plurality of data alerts from the demodulation circuit, and (v) determine the wireless data signals based on the plurality of data alerts.
 2. The wireless power transfer system of claim 1, wherein the initial beaconing process is a staircase beaconing protocol.
 3. The wireless power transfer system of claim 2, wherein the staircase beaconing protocol includes a plurality of beacons of power for transmission to detect the wireless power receiver system.
 4. The wireless power transfer system of claim 3, wherein each of the plurality of beacons of power are configured to detect the wireless power receiver system at one of a range of couplings between the transmitter antenna and the receiver antenna.
 5. The wireless power transfer system of claim 4, wherein the plurality of beacons of power include, at least, a beacon for detecting a high coupling, a beacon for detecting a moderate coupling, and a beacon for detecting a low coupling.
 6. The wireless power transfer system of claim 4, wherein the plurality of beacons of power includes a first beacon of power configured to detect the wireless power receiver system at a first coupling range and a second beacon of power configured to detect the wireless power receiver system at a second coupling range, wherein the first beacon of power has a first voltage and the second beacon of power has a second voltage, and wherein the second voltage is greater than the first voltage.
 7. The wireless power transfer system of claim 1, wherein the transmitter controller is further configured to determine instructions for the automatic bias control and gain control based, at least in part, on the initial beaconing process.
 8. The wireless power transfer system of claim 1, wherein respective resistance values of the first digital potentiometer and the second digital potentiometer are set by the transmitter controller.
 9. The wireless power transfer system of claim 8, wherein the transmitter controller sets the respective resistance values of the first digital potentiometer and the second digital potentiometer based on sensed current associated with the wireless data signals and sensed coupling strength between the transmitter antenna and the receiver antenna.
 10. The wireless power transfer system of claim 1, wherein the transmitter antenna is configured to operate based on an operating frequency of about 6.78 MHz.
 11. The wireless power transfer system of claim 1, wherein the wireless power transmission system is configured to transmit the AC wireless signals to the wireless power receiver system when the medical device resides within a human body.
 12. The wireless power transfer system of claim 1, wherein the medical device is configured as an implantable medical device.
 13. A wireless power transfer system comprising: a medical device comprising a wireless power receiver system including a receiver antenna; and a wireless power transmission system including: a transmitter antenna configured to couple with the receiver antenna of the medical device and transmit alternating current (AC) wireless signals to the receiver antenna, the AC wireless signals including wireless power signals and wireless data signals, the wireless data signals generated by altering electrical characteristics of the AC wireless signals at the wireless power receiver system; an amplifier that is configured to receive a driving signal at a gate of at least one transistor and invert a direct power (DC) input power signal to generate the AC wireless signals at an operating frequency; and at least one sensor configured to detect electrical information associated with the electrical characteristics of the AC wireless signals, the electrical information including one or more of a current of the AC wireless signals, a voltage of the AC wireless signals, or a power level of the AC wireless signals, wherein the electrical characteristics include a voltage of the wireless power signals; a demodulation circuit configured to (i) receive the electrical information from the at least one sensor, (ii) apply automatic bias control and gain control to the electrical information to generate a modified electrical information signal (iii) detect a change in the modified electrical information signal, (iv) determine if the change in the modified electrical information signal meets or exceeds one of a rise threshold or a fall threshold, (v) if the change exceeds one of the rise threshold or the fall threshold, generate an alert, (vi) and output a plurality of data alerts, wherein the demodulation circuit is configured to detect a change in the modified electrical information signal by determining a voltage rate of change of a voltage of the modified electrical information signal, and wherein the demodulation circuit includes a comparator circuit configured to (i) receive the voltage rate of change, (ii) compare the voltage rate of change to a rising rate of change, and (iii) determine that the change in the electrical characteristics meets or exceeds the rise threshold, if the voltage rate of change meets or exceeds the rising rate of change; and a transmitter controller configured to (i) configure the driving signal based, at least, on an operating frequency and an initial beaconing process, the initial beaconing process for determining presence of the wireless power receiver system at a coupling between the transmitter antenna and the receiver antenna, (ii) determine amplifier voltage instructions for the amplifier based on the initial beaconing process, (iii) drive the amplifier by providing the driving signal and the amplifier voltage instructions to the amplifier, (iv) receive the plurality of data alerts from the demodulation circuit, and (v) determine the wireless data signals based on the plurality of data alerts.
 14. The wireless power transfer system of claim 13, wherein the comparator circuit is further configured to (i) receive the voltage rate of change, (ii) compare the voltage rate of change to a falling rate of change, and (iii) determine that the change in the electrical characteristics meets or exceeds the fall threshold, if the voltage rate of change meets or exceeds the falling rate of change.
 15. The wireless power transfer system of claim 13, wherein the demodulation circuit includes a set/reset (SR) latch in operative communication with an output of the comparator circuit.
 16. The wireless power transfer system of claim 13, wherein the wireless power transmission system is configured to transmit the AC wireless signals to the wireless power receiver system when the medical device resides within a human body.
 17. The wireless power transfer system of claim 13, wherein the medical device is configured as an implantable medical device.
 18. The wireless power transfer system of claim 13, wherein the transmitter antenna is configured to operate based on an operating frequency of about 6.78 MHz.
 19. The wireless power transfer system of claim 13, wherein the initial beaconing process is a staircase beaconing protocol.
 20. The wireless power transfer system of claim 13, wherein the transmitter controller is further configured to determine instructions for the automatic bias control and gain control based, at least in part, on the initial beaconing process. 